Environment

9:18 am

Wed July 25, 2012

Northwest coastal waters slightly caffeinated, study finds

The Northwest's love of coffee is leading to caffeine spilling into coastal waters.

Diane GillelandFlickr

The Northwest is known for its love of coffee. Now evidence of that is showing up in the Pacific Ocean. Researchers have found low levels of caffeine at half a dozen locations on the Oregon Coast.

Caffeine has previously been found to be pervasive in Puget Sound and has even turned up in relatively pristine Barkley Sound on the outer coast of Vancouver Island.

A Portland State University graduate student collected water samples at 14 coastal beaches and seven nearby river mouths, and samples taken after heavy stormwater runoff contained traces of caffeine.

The results seem to indicate that wastewater treatment plants are effective at removing caffeine, but that high rainfall and combined sewer overflows flush the contaminants out to sea, a press release announcing the study results said. The results also suggest that septic tanks, such as those used at the state parks, may be less effective at containing pollution.

Study co-author Elise Granek said the find raises more questions than answers, including how caffeine at low levels affects local marine life.

"We are several steps away from being able to tell what the actual impacts are on the organisms," Granek said. "But we do know from this other component of the study that the approximate level of caffeine that we saw at Cape Lookout is enough to cause cellular stress to organisms."

Caffeine is found in many food and beverage products as well as some pharmaceuticals, and caffeine pollution is directly related to human activity (although many plant species produce caffeine, there are no natural sources of the substance in the Northwest). The presence of caffeine may also signal additional anthropogenic pollution, such as pesticides, pharmaceuticals and other contaminants.

Even “elevated levels” of caffeine are measured in nanograms per liter, well below a lethal dose for marine life. However, an earlier study by Rodriguez del Rey and Granek on intertidal mussels showed that caffeine at the levels measured in this current study can still have an effect despite the lower doses.

“We humans drink caffeinated beverages because caffeine has a biological effect on us – so it isn’t too surprising that caffeine affects other animals, too,” says Granek. Previous studies have found caffeine in other bodies of water around the world, including the North Sea, the Mediterranean, Puget Sound, Boston Harbor and Sarasota Bay, Fla.